Manchester United have failed to hit their high standards - John O'Shea

Sunderland defender John O'Shea reckons his former club Manchester United have failed to keep up to their high standards this season.

The Irish veteran centre-back helped his team to a stunning 2-1 win over the Red Devils at the Stadium of Light on Saturday, handing the visitors their seventh loss in the league.

New recruit Wahbi Khazri gave Sunderland the lead before Anthony Martial levelled proceedings just before the break. A bizarre own goal credited to David De Gea eight minutes from time gave Sam Allardyce's team maximum points.

"Because of the season they're having and the amount of injuries they've got, it's difficult for them," O'Shea told The Express.

"They don't have as many players as they used to and while they're still a good team, United are not challenging where they want to be in the table."

The 34-year-old is shocked at the current failings of his former club, something he did not expect given their strong squad depth and rich backings off the field.

"That is the given beforehand [challenging for the title] when you look at the squad and the budgets and what is spent to get there," he said.

"Now it's about adjusting. There have been big injuries, they have lost some very important players and in the Premier League, the quality is increasing.

"You are having to blood two young lads at full-back [Cameron Borthwick-Jackson and debutant Donald Love], they did well but it's tough. I was a young lad coming into a team that was winning the league so it was that bit easier, but if you're not finishing first or second, there is more pressure."

One thing that did annoy O'Shea after Sunderland's stunning victory at the weekend was how everyone preferred to lay into United's failings than give his team the credit they deserve.

"If we stay in the Premier League, everyone can talk about Manchester United as much as they want," he said. "But we deserve a bit of credit and in the end could have won it more comfortably than we did."

Sunderland have a chance to climb out of the relegation zone on Feb. 27 when they travel to London to take on West Ham United, where a win could see them go above Newcastle United and Norwich City.